Since its introduction into this country, the gypsy moth has been recognized as a serious pest on a number of forest and ornamental trees. The damage is inflicted by extensive feeding of the larval stages on tree foliage. Mature larvae drop to the ground to pupate, and the emerging adult females, which are unable to fly, deposit eggs on suitable surfaces near the emergence site. The eggs hatch in the mid to late spring and the newly hatched larvae move up the tree trunk to reach the tree canopy and feed. Corliss, John M., "The Gypsy Moth" Yearbook of Agriculture, 1952, and Tolan, Roberta, "The Detection and Control of Gypsy Moth (Lamantria dispar) Using Pheromone Attractant," Insect Behavior (EN 507), Colorado State University, 1995, discuss the effects of defoliation by the gypsy moth.
In addition to the gypsy moth, there exists numerous other tree pests that feed on tree foliage. Such pests include those that cannot fly and therefore can only reach the foliage areas by crawling up the trunk of trees with no other ground contact. The problems associated with these tree pests are well known. For example, Quayle, Henry J., "Insects of Citrus and Other Subtropical Fruits," 1938, discusses the effects of species such as the Argentine ant, the fire ant, and the Fuller rose beetle on trees, and in particular, on citrus trees. Quayle discloses, in particular, that injury caused by the Fuller rose beetle is characterized by the irregular areas eaten away around the margins of the leaf, and that young and recently budded trees are most effected.
Reuther et al., "Biological Control of Citrus Insects," The Citrus Industry", Vol. 4, 1978, also discloses the harmful effects resulting from ant infestations in citrus orchards. In particular, the Reuther reference discloses that the ants bring about increases in the infestations of many damaging species such as scale insects and mealy bugs. Ebeling, Walter, "Subtropical Fruit Pests," Biological Control, 1959, supports Reuther et al. in disclosing that the presence of ants, which are attracted to trees in which the sugary excrement (honey dew) of insects such as the aphids, mealy bugs, unarmored scales, cottony-cushion scale, and white flies, are present, in citrus orchards has long been known to be undesirable because of their ability to decrease the effectiveness of the natural enemies of the crop pests.
Carman, Glenn E., "The Pest Control Circular," Sunkist Growers, Inc., Nos. 545 (1986) and 546 (1987), discloses the impact of the Fuller rose beetle on exporting citrus to Japan.
For years, various apparatus and methods have been proposed, or used, but with little or no success. For instance, a band of a sticky substance or other deterrent applied directly on the surface of the tree trunk has been used. However, environmental factors such as rainfall, irrigation waters, dust, leaves, others tree parts and other debris have soon rendered such bands ineffective.
Quayle, in particular, discloses the use of tree barriers such as cotton and tanglefoot bands to control a particular species, i.e., the Argentine ant, in citrus orchards. As discussed herein, such devices are subject to environmental influences. Quayle also discloses the use of poisoned baits placed in containers such as paper cups, spice tins and the like and attached to tree trunks. However, as discussed herein, the use of poison to control such pests is highly undesirable.
Carman discloses treatments including foliar applications, skirt pruning with trunk application of chemicals and skirt pruning with trunk barriers such as discussed above to control a number of pests, including snails, ants and Fuller rose beetle. Carman discloses, in particular, the application of highly viscous materials, for example, those that contain polybutene or other hydrocarbon materials, to trunk surfaces. Carman discloses, however, that such methods have disadvantages. For example, Carman discloses that skirt pruning alone is insufficient to control pests and that chemical treatment, although effective, has drawbacks. Carman also discloses that the use of viscous materials on the trunk of a tree may cause bark damage or girdling if applied directly or even if applied on a porous material.
U.S. Pat. No. 5,561,941 discloses the use of a strip of material that contains a coating having specified properties to restrict the movement of insects up the trunk of a tree. As discussed herein, the use of such a device is subject to environmental influences.
U.S. Pat. No. 4,098,018 discloses an insect trap that is attachable to a tree. The trap contains a canister attached thereto to deliver an insecticide. As discussed herein, the use of such substances is undesirable.
U.S. Pat. No. 5,353,556 discloses a device for preventing pests from crawling up the trunk of a tree. The device, which involves positioning a combination of tactic, ultraviolet light and other barriers in the path of the pest, would require special molding and therefore would not be cost effective.
Accordingly, there remains a need for better apparatus and methods that are capable of controlling tree pests.